Questions tagged [circuit-analysis]
Circuit (Network) analysis is the process of finding the voltages across, and the currents through, every component in the network. Consider using in conjunction with tags for the particular analysis technique(s) in question: "nodal-analysis", "mesh-analysis", "superposition", etc.
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Need help to identify an unmarked SOT23-5 IC
I have come across a PCB which is a vibration sensor (switch) based motion detection logic, where on any vibration is detected, the circuit will turn on/off a load. It works in same way as a Push ...
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Transfer function of an electromechanical system
In this exercise I am asked to find θc(s)/θR(s), of which I am given the following indications.
In the system shown in the figure, the motor is an armature-controlled dc motor, and there is also a ...
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Can this Raspberry Pi UPS circuit work?
I created following UPS circuit to shutdown my Raspberry Pi 3A+ properly:
I would really appreciate if somebody can review my circuit. I know it's a little bit hard to read, but I'm sorry. I'm a ...
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Where does the 1 V voltage come from?
I have a PLC with many digital open collector outputs connected similarly to the schematic below.
If I use a multimeter and measure the voltage between the two points in the schematic, it is showing 1 ...
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Appoximation of a transient response of a more complex circuit
I have a "complicated" circuit that I want to approximate as a simple harmonic oscillator. More info below.
I have a parallel LRC circuit, with some extra input and output load resistors and coupling ...
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How does this amplifier stage work?
I was searching different circuits to produce sinusoidal waves and came across one that seems simple but I do not understand how it works. It has the usual band pass filter (in this case it was a Wien ...
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Find the open-circuit voltage ratio of the following two-port network
This is the circuit:
Here's what I have done:
I converted the part before the input of the two-port network (1 capacitor and 2 resistors) into another two-port network and derived the transmission ...
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How does this capacitance measurement op-amp circuit work?
I'm studying this scientific paper where a capacitance measurement is done with the circuit shown at page 3. For simplicity I reported it here:
A sinusoidal signal is applied at the input through a ...
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How to find new ABCD parameters when reversing 2-port network
I have an ABCD matrix represenataion which is defined as:
For such a problem, what approach should I follow in order to organize the new ( reversed) network ports voltages and currents properly. I ...
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Where should I take the measurement from to find the correct attenuation level of a resistive pi attenuator?
I am currently designing a resistive attenuator for an RF project I'm working on. I wanted to have several resistance combinations to obtain various attenuation levels (1-8 dBs). When I calculate the ...
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Calculating the poles of a Circuit
I have been reading Behzad Rahzavi's Analog Design book to prepare for interviews and have come across a discussion on calculating poles that confuses me.
In the following example 6.15 the book ...
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PSpice Error: Voltage source and/or inductor loop involving V_Vin
I'm trying to simulate the circuit in Pspice; the first few times it worked. However, I got an error when I tried to create a new page and copy all the circuits on it in order to do some circuit ...
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Negative PSRR of Two-Stage Op Amp
From page 4-9 of this lecture note https://pallen.ece.gatech.edu/Academic/ECE_6412/Spring_2004/L180-PSRR-2UP.pdf, it gives example on how to model a Two-Stage Op Amp to find the PSRR- when \$V_{Bias}\$...
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High pass filter simulation involving loop outside the circuit
I am trying to model a tweeter filter circuit from GR Research's X-CS Encore loudspeakers, more specifically get the transfer function Vo/Vi. I have included an example of how I did it for the woofer ...
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What is the purpose of connecting the series capacitor to the low side P- channel MOSFET gate?
The datasheet describes CAOUT as a decoupling capacitor. Not sure how it is so ?
My guess on the working of the circuit:
When AOUT is high, CAOUT is gradually charged with +(on left) and right ...
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Selecting the proper resistors in a bi-directional level shifter?
How do you calculate the values of R1 and R2 in the circuit for a Bidirectional Logic Level Shifter if the high and low voltages are known?
Searching on the Internet I found 10K is a good option to ...
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Dependent current sources in Thevenin equivalent
In this question to find out ZTH, why have we put a 1 A current source?
Can't we just short circuit the VTH potential and find the current across that to find ZTH?
Source: https://i.sstatic.net/9KVGu....
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Design of a DC motor controller
I want to design a control system to a DC motor using descrite component and not IC component. At the aim is to control the speed of that motor, but at the first time I want to design the inner ...
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Connection from breadboard to stripboard
I already have my circuit placed on breadboard. Now I need to transfer it on stripboard. My question is I can just transfer the exact same connection and placement on stripboard right? I don't need to ...
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Trying to perform transient frequency response with LTspice or Microcap, TL494 compensation
I have tried to do Bode plot of my uncompensated plant by myself in LTspice 17.1, but the result looks strange to me. This topic is a follow-on to this one.. I have no clue why it comes with 290 ...
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Can anyone help me find this IC SZ9KH?
I tried looking for datasheet for SZ9KH but can't find anything. I encountered this IC on a board that needed to be amplified.
Mostly i want to know how does the amplification works? Is it an op-amp ...
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How to solve the equivalent circuit of the induction motor?
Let's say I have below given equivalent circuit of the induction motor.
The parameters \$R_S\$, \$R_{Fe}\$, \$R_{load}\$, \$X_M=2\pi\cdot f\cdot L_M\$ and \$X_L=2\pi\cdot f\cdot L_L\$ are known and ...
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About MOSFET circuit behavior
When I look at the waveforms of simulated circuits, how do I know when their behavior (for example flipping value stored on a node, or an unexpected drop in strong level value...) is due to MOSFET ...
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Sensitivity of Inrush Current Circuit
I'm new to LTSpice and analog design - I'm having a bit of a struggle getting a feel for the behavior of this inrush limiting circuit. Stole the design from another SE post, but playing with the ...
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RHP pole of two stage OTA
I learnt that for any amplifier (with some capacitor) if we short/open the capacitor and the polarity of gain changes, it is a sign of RHP zero.
Now, while applying the same analysis I obsevred that ...
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Current Direction and Voltage Polarity in Capacitor/Inductor Circuits
I believe that this question may be simple for those with a little more experience, but it is still puzzling me.
Studying capacitance/inductance, I understand that the capacitor in the DC case behaves ...
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Can anyone help me figure out what this circuit does?
I wanted to see if anyone might be able to help me understand this circuit board a bit better. I am trying to trace some issues I'm having with my car stereo and this board is the furthest I can trace ...
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Small signal analysis of MOSFET circuit
The other day I got the following exercise on one of my exams:
For those who don't speak German, for transistor 1 lambda is 0, but not for the others. The backgate-effekt should be neglected ...
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How to measure 10bit SAR ADC 's input Dynamic range after switch 9 time?
I want to know 10 bit SAR ADC , supply voltage 0.5V , Vcm based , after DAC switch 9 times , how to measure DAC input Dynamic range ? I need to know voltage range that I can use Voltage to time ...
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How should fuse selection be made in discrete-time alternating current?
My V(t) signal progresses for hours as 0.75 seconds on,5 seconds off.(Let assume V(t)=I_lamp(t),R_lamp=1 ohm)
The general formula for fuse selection at room temperature is:
In summary,what should I ...
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555 PWM circuit set frequency shifting after 2 months
Please refer to post PWM generator circuit review for initial simulation and bugs on the circuit.
In general, the circuit works very well and I can control a 12V fan with the PWM output of the 555 ...
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finding state space equation in x=Ax+Bu form
Can anyone please help me to find the state space equation of this circuit diagram in the form of x=Ax+Bu?
The equation I am getting is not giving me square matrix. Can anyone help please?
These are ...
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What is the effective value of the current of the voltage generator?
I need help with this task, if anyone had a similar problem it would help me.
The task is:
A voltage generator is connected to the primary of an ideal transformer, transformation ratio n
rms values ...
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karnaugh table issues
Hello,I have this truth table.I did this table and I am creating a demultiplexer 1 in 2.Not multiplexer.
Second,I did
and that
I gave and those
Am I right?I want to confirm that I have done it all ...
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Left half and right half plane zeros
In the common-source on the left, one can solve for the transfer function and see that there's a right-half plane zero at \$s_z = +g_m/C_{gd}\$. For the source-follower on the right, similarly you can ...
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Nonlinear circuit and RLC
I'm trying to solve the following question from "Communication Circuits: Analysis and Design"
by Donald T. Hess:
For the circuit shown in Fig. \$1.P1\$, determine an expression for \$v_o(t)\...
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Time delay in lumped element delay line
I was trying to analyse a lumped element-delay line by changing the frequency and measuring \$ V_{in}\$ , as shown in the graph the goal of my analysis is to find the time-delay and the attenuation ...
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Voltage-divider bias common emitter calculations are yielding unexpected results
I performed an analysis on this voltage-divider-feedback common emitter. My result in simulation is relatively close, but doesn't quite check out. Where did I go wrong? I'm new to this and ...
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How does this timer 555 and transistor circuit work?
Is this the way this circuit works ?
If vref = 5v on the pin #5, then Vthreshold = 5v, and Vtrigger = 2.5v
With Vthreshold = 5v, if voltage on pin #6 Vp6 > 5v, then Vp3 is Vo = 0
With Vtrigger = ...
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Proving the state of a diode in a clamping circuit?
simulate this circuit – Schematic created using CircuitLab
So i have this positive clamper right here. So the diode will be ON at a negative source voltage since the anode side will see 5V which ...
user263783
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Adding Line Out / Sub Out to LG soundbar
I have LG Soundbar with wireless sub. I am trying to add Line output, so i could connect a wired sub.
I took some pictures of the boards and chips. If someone could point me in right direction on ...
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How do I find Vs in this circuit with a 2:1 ideal transformer?
How do I find Vs given that V0(to the left) is 10L30degrees? I started by finding that the current on the 10 ohm resistor is 1L30 degrees, and then using kirchoff's law, the current on the tranformer ...
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Need help for pointing out, source follower circuit with current source, designing NMOS
I'm not sure did I solve this problem right.
I made \$ r_{o2} \$ , which is resistance looking at Q2 drain.
So I can get
$$ g_{m,Q3} = 1.8m(A/V) $$
from
$$A_v = \frac{r_{o2} || r_{o3}}{1/g_m + (r_{o2} ...
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Computing the maximum power that this opamp provides to the load Rl without occurring distortion
Here's the schematic:
So first stage is a differential amplifier where vo1 =3.72V in DC (Vin= 0). In this stage i can say AmplVo1 = gainStage1 * AmplVi where distortion only happens when vo1 is ...
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Problem understanding transfer functions of second order filters
The transfer function of any second order filter can be found by analyzing the circuit using the Laplace transform.
For example the transfer function of a second order low pass passive RLC filter ...
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Are there errors in the description of this circuit?
Background
The circuit describes the operation of a variable voltage power supply. In the description below the circuit diagram there are errors. Read through the description and note down any errors....
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Electric power of the light bulbs in a circuit with diodes
Let \$R_1 = 1 \: \Omega, R_2 = 2 \: \Omega, R_3 = 3 \: \Omega, ...R_{10} = 10 \: \Omega\$ be the resistances of the light bulbs depicted in the circuit below and let \$U = 2 \: V\$ be the voltage of ...
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Trouble understanding how dependent current sources affect a circuit (Two-port networks)
While reviewing a problem from my recent test on two-port networks I noticed that it made its way online.
When someone was explaining the solution they utilized a point that I just completely missed. ...
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First principles modeling of op amp CMRR
Introduction
I'm trying to analyze an op amp circuit from first principles (i.e. without using the two rules of ideal op amp analysis -- virtual short circuit and infinite input impedance). The ...
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Determining gain, KCL/KWL (Basics)
Below is a pi model schematic of a cascaded amplifier. The goal is to find the gain with Rp as load.
So the gain would be:
\$ A = \frac{V_{out}}{V_{in}}\$. So i set out to find \$V_{out}\$ in terms ...
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